This document relates to cellular telecommunication systems, especially to a heterogeneous network where one or more low-power nodes are deployed in a macro base station's coverage.
Cellular communication systems are being deployed all over the world to provide not only voice services, but also mobile broadband data and multimedia services. There is an ever-growing need for higher bandwidth because new mobile applications are continuously being released that consume higher and higher amount of data, e.g., for video and graphics. As mobile system operators deploy these bandwidth-hungry applications and increase the geographic areas covered by broadband mobile services, there is an ongoing need to cover every square inch of an operator's coverage area with high bandwidth connectivity.
As the spectrum efficiency for the point-to-point link already approaches its theoretical limit, one way to increase the capacity of a network to simultaneously service more and more mobile stations is to split big cells into smaller and smaller cells. When the cell becomes closer to each other, the adjacent cell interferences become more severe, the cell splitting gain saturates. Furthermore, nowadays it is more and more difficult to acquire new sites to install base stations for the operators and the costs are also higher and higher. Therefore, cell-splitting cannot fulfill the bandwidth demands.
Improvements to the operation of cellular wireless networks are needed.